Electric bell



Filed Aug. 5, 1931 INVENTO. iv dofas 1% 7260 Y g (E $9 A TTORNE Y Patented May 15, 1934 UNITED STATES PATENT OFFICE This invention relates to new and useful improvements in an electric bell.

The invention has for an object the construction of an electric bell which is characterized by the energization of the solenoid to cause the hammer to strike during the greater length of the amplitude of motion of the hammer.

Another one of the objects of this invention is the provision of switches arranged in a manner so as to maintain the energization of the solenoid which operates the striking hammer of the bell for the greater period of time of the motion of the hammer.

It is general construction in bells to energize a solenoid which moves the striking hammer, and

immediately upon motion of the striking ham- I mer towards the solenoid, the circuit through the solenoid is immediately broken. Thus a weak stroke of the hammer is produced in comparison with the instant invention wherein the solenoid is energized during the greater portion of the stroke of the hammer.

A further object of this invention is the provision of a means for delaying the re-energization of the solenoid until the full return of the armature after the solenoid is de-energized.

A still further object of this invention is the construction of a bell of the class mentioned which is of simple durable construction, dependable in use and eflicient in operation and which can be manufactured and sold at a reasonable cost.

For further comprehension of the invention, and of the objects and advantages thereof, reference will be had to the appended. claims in which the various novel features of the invention are more particularly set forth.

In the accompanying drawing forming a material part of this disclosurez-- The figure illustrates a schematic diagram of the bell and the electrical connections thereof.

The bell comprises an acoustic member 10 strikeable by a hammer 11. This hammer is pivotally mounted intermediately at 12. A strong spring 13 normally moves the hammer away from the member 10. A moveable contact 14 is pivotally supported intermediately at 15 and a weak spring 16 urges the moveable contact against the hammer 11. Projections 17 and 18 mounted upon the moveable contact arm 14 constitute the contact points of the arm. A stationary contact 19 is spaced to the front of the projection 17 and is so located that the spring 13 may pivot the hammer 11 so that it rests against the projection 18 and the projection 17 in turn rests against the stationary contact 19. A stop 20 is located between the contact arm 14 of the hammer 11 for the purpose of allowing the spring 16 to pivot the contact arm 14 to follow the hammer 11 through the greater length of its stroke against the acoustic member 10. A control circuit is provided and constitutes a source of current 21 connected with a lead 22 having a push button switch 23 in series and terminating in connection with the contact arm 14. The circuit may then continue through the projection 17, the stationary contact 19, a lead 24, a solenoid 25, and a return lead 36 to the source of power 21. The solenoid 25 is connected with the hammer 11 so that upon ener gization it causes the hammer to move against the acoustic member 10.

A second circuit extends from the stationary contact 19 along a lead 27 through the windings of a magnet 28 and through a lead 29 to the return to the source of power 21. A lead circuit exists from the moveable contact through the projection 18, the clapper 11, a lead 30, a switch 31 controlled by the operation of the electromagnet 28 along the lead 27, lead 24, through i the solenoid 25 and the return lead 26 and to the source of power 21.

The operation of the device may be traced by assuming the switch 23 opened, in which case the strong spring 13 moves the hammer 11 so that the hammer is in contact with the projection 18 and the projection 17 is in turn in contact with the stationary contact 19. This is the position of rest or the inoperative position of the bell. Upon closing the switch 23, an electric circuit will exist from the battery 21, along lead 22 to the moveable contact 14. From here the current continues through the projection 11"], the stationary contact 19, the lead 24, through the solenoid 25 and along the lead 26 to the battery 21. The solenoid 25 becomes energized and starts moving the clapper 11 towards the acoustic member 10.

A second circuit also exists simultaneous with the first circuit and extends from the contact 19 along the lead 27 through the windings of the magnet 28, along the lead 29 back to the source of current 21. This second circuit causes the simultaneous energization of the magnet 28 and the solenoid 25. When the magnet 28 becomes energized the switch 31 closes and causes the existence of a third circuit which may be traced from the moveable contact 14 through the projection 18 to the clapper 11 and then along the lead 30, through the switch 31, the lead 27, the lead 24, through the solenoid 25 and the lead 26 back to the battery 21. The switch 31 is hingedly mounted at 31 and a spring 31* normally urges the switch into an open position. This third circuit remains even if the contact 17 leaves the contact 19. This is true because there are two circuits simultaneously existing through the magnet 28 when the contacts 17, 19 and 18 are closed. One circuit exists from the battery through the contacts 1'7 and '79, through the magnet 28 and back to the battery through the lead 29. The second circuit exists from the battery through the contacts 17 and 18, along the lead 30, through the switch 31, through the magnet 28 and back to the battery. Therefore, when the first circuit through the magnet 28 is brokenby the separation of the contacts 1'7 and 19, the current can continue to keep the magnet 28 energized through the second circuit and continue to keep the switch 31 closed. During this period the clapper 19 will be drawn by power towards the acoustic member 10. When the moveable contact 14 reaches the stop 20, the third circuit will be broken at the projection v18 since the projection now remains stationary while the clapper finishes its stroke and strikes the acoustic member.

After the third circuit is broken, all circuits will be broken since the moveable arm 14 with the contacts 17. and 18 is in a position in which neither thesolenoid 25 loses its energy and the clapper 11 is free to be moved back tothe initial position by the spring 13. After the clapper moves back, it engages against the projection 18 and moves the moveable arm 14 back to its original position. The device is now ready for operation again.

While I have shown and described the preferred embodiment of my invention, it is to be understood that I do not limit myself to the precise construction herein disclosed and the right is reserved to all changes and modifications coming within the scope of the invention as defined in the appended claim.

Having thus described my invention, what I clai n as new, and desire to secure by United States Letters Patent is:-

In a device of the class described, a stationary contact, a movable armature spaced from said stationary contact, a movable arm between said contact and armature, means for urging said arm against said armature and away from said contact, means for urging said armature into a normal position for holding said arm against said contact, a solenoid having its core connected with said armature for moving the armature away from said normal position, a relay having a core and a self opening switch arranged so that energization of the core closes the switch, a circuit for closing said relay switch comprising in series a source of power, a hand switch, said arm, said contact, and the core of said relay, another circuit for moving said armature from said normal position comprising in series said source of power, said hand switch, said arm, said armature, said switch of the relay, and said solenoid, and a peg to arrest the arm from following the armature located near the end of the stroke of the armature for opening said latter mentioned circuit, said solenoid being shunted across the core of said relay.

NICHOLAS FRANCO. 

